I agree. I built a St. Louis vertical for a club picnic a few years ago.
Even with eight tuned radials we couldn't hear a thing. The band wasn't all
that active at the time but it was so quiet we wondered if something was
wrong with the little QRP rig we were using. We tossed a horizontal wire
dipole over a low tree and out popped the signals. The band still wasn't
great, but at least we worked a few people. With that vertical we literally
could not hear a single station.
73 - JC, k0hps@amsat.org
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com]On Behalf Of ersmar@comcast.net
Sent: Sunday, June 04, 2006 4:08 PM
To: Tom Osborne; Towertalk
Subject: Re: [TowerTalk] Helically wound verticals
Tom:
You are likely to be disappointed with these ground-mounted verticals
for FD contesting for the following reasons:
1. FD is a domestic US (i.e., non-DX) contest for which a low dipole would
work better than a vertical on 80, 40 and possibly 30M.
2. A short, loaded vertical will not be as efficient and effective as a
full-size 1/4WL radiator.
3. I'm presuming you're going to ground-mount these verticals over a
minimal ground field, resulting in even lower efficiency.
If you want to construct something with PVC, let me suggest either a
single-pole support, 30 feet tall, for two inverted V's for 80 and 40, or
two guyed poles 30 feet tall to support spider-web dipoles (one common coax
feedline) for all three bands. Check out this site on NVIS antennas for
ideas: http://www.w0ipl.com/ECom/NVIS/nvis.htm . A Google or Yahoo! search
will yield even more sources and info.
73 de
Gene Smar AD3F
-------------- Original message ----------------------
From: "Tom Osborne" <w7why@verizon.net>
> Hi All
>
> Some years back, there was an article, I believe in QST, about some
vertical
> antennas wound on 2 pieces of pvc pipe. They were for 40, 30 and 20. The
> bottom section was wound for 30/40 and you changed the top section to
change
> from 30 to 40. There were 2 sections that were wound for 20. This was
all
> built on a pvc pipe frame. Can anyone steer me to that article? I'd like
> to make some for field day this year. Where our club picked to go (why
I'll
> never know) there are few if any trees for antennas.
>
> If someone could scan it for me I'd sure appreciate it as I don't have
many
> QST's around any more. Thanks and 73
> Tom W7WHY
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|